Spring5（16）- 基於 註解 的 AOP 實現事務控制

1 工具類

• ConnectionUtils

/**
 * 連接的工具類
 */
@Component("connectionUtils")
public class ConnectionUtils {
    private ThreadLocal<Connection> tl = new ThreadLocal<>();

    @Autowired
    private DataSource dataSource;

    /**
     * 獲取當前線程的連接
     *
     * @return
     */
    public Connection getThreadConnection() {
        Connection conn = tl.get();

        try {
            if (null == conn) {
                // 從數據源獲取一個連接，並存入ThreadLocal
                conn = dataSource.getConnection();
                tl.set(conn);
            }
            return conn;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 把連接和線程解綁
     */
    public void removeConnection(){
        tl.remove();
    }
}

---

• 切面類
  如果使用註解，後置通知和最終通知順序會錯亂。所以需要使用環繞通知

/**
 * 事務管理的相關工具類
 */
@Component("txManager")
@Aspect // 表明當前類是切面類
public class TransactionManager {

    @Autowired
    private ConnectionUtils connectionUtils;

    @Pointcut("execution(* com.tzb.service.impl.*.*(..))")
    private void pt1() {

    }

    // 開啓事務
    public void beginTransaction() {
        try {
            connectionUtils.getThreadConnection().setAutoCommit(false);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    public void commit() {
        try {
            connectionUtils.getThreadConnection().commit();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void rollback() {
        try {
            connectionUtils.getThreadConnection().rollback();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void release() {
        try {
            connectionUtils.getThreadConnection().close();
            connectionUtils.removeConnection();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Around("pt1()")
    public Object aroundAdvice(ProceedingJoinPoint pjp) {
        Object rtValue = null;
        try {
            // 1.獲取參數
            Object[] args = pjp.getArgs();
            // 2.開啓事務
            this.beginTransaction();
            // 3.執行方法
            rtValue = pjp.proceed(args);
            // 4.提交事務
            this.commit();

            // 返回結果
            return rtValue;

        } catch (Throwable e) {
            //5.回滾事務
            this.rollback();
            throw new RuntimeException(e);
        } finally {
            // 6.釋放資源
            this.release();
        }
    }
}

2 DAO

@Repository("accountDao")
public class AccountDaoImpl implements IAccountDao {

    @Autowired
    private QueryRunner runner;

    @Autowired
    private ConnectionUtils connectionUtils;

    @Override
    public List<Account> findAllAccount() {
        try{
            return runner.query(connectionUtils.getThreadConnection(),"select * from account",new BeanListHandler<Account>(Account.class));
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public Account findAccountById(Integer accountId) {
        try{
            return runner.query(connectionUtils.getThreadConnection(),"select * from account where id = ? ",new BeanHandler<Account>(Account.class),accountId);
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void saveAccount(Account account) {
        try{
            runner.update(connectionUtils.getThreadConnection(),"insert into account(name,money)values(?,?)",account.getName(),account.getMoney());
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void updateAccount(Account account) {
        try{
            runner.update(connectionUtils.getThreadConnection(),"update account set name=?,money=? where id=?",account.getName(),account.getMoney(),account.getId());
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void deleteAccount(Integer accountId) {
        try{
            runner.update(connectionUtils.getThreadConnection(),"delete from account where id=?",accountId);
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public Account findAccountByName(String accountName) {
        try{
            List<Account> accounts = runner.query(connectionUtils.getThreadConnection(),"select * from account where name = ? ",new BeanListHandler<Account>(Account.class),accountName);
            if(accounts == null || accounts.size() == 0){
                return null;
            }
            if(accounts.size() > 1){
                throw new RuntimeException("結果集不唯一，數據有問題");
            }
            return accounts.get(0);
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

3 Service

@Service("accountService")
public class AccountServiceImpl implements IAccountService {

    @Autowired
    private IAccountDao accountDao;

    @Override
    public List<Account> findAllAccount() {
       return accountDao.findAllAccount();
    }

    @Override
    public Account findAccountById(Integer accountId) {
        return accountDao.findAccountById(accountId);

    }

    @Override
    public void saveAccount(Account account) {
        accountDao.saveAccount(account);
    }

    @Override
    public void updateAccount(Account account) {
        accountDao.updateAccount(account);
    }

    @Override
    public void deleteAccount(Integer acccountId) {
        accountDao.deleteAccount(acccountId);
    }

    @Override
    public void transfer(String sourceName, String targetName, Float money) {
        System.out.println("transfer....");
            //2.1根據名稱查詢轉出賬戶
            Account source = accountDao.findAccountByName(sourceName);
            //2.2根據名稱查詢轉入賬戶
            Account target = accountDao.findAccountByName(targetName);
            //2.3轉出賬戶減錢
            source.setMoney(source.getMoney()-money);
            //2.4轉入賬戶加錢
            target.setMoney(target.getMoney()+money);
            //2.5更新轉出賬戶
            accountDao.updateAccount(source);

            int i=1/0;

            //2.6更新轉入賬戶
            accountDao.updateAccount(target);
    }
}

4 bean.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd"> <!-- bean definitions here -->

    <!--配置spring 創建容器時要掃描的包-->
    <context:component-scan base-package="com.tzb"></context:component-scan>

    <bean id="runner" class="org.apache.commons.dbutils.QueryRunner" scope="prototype"></bean>

    <!--配置數據源-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/spring5?userSSL=false"></property>
        <property name="user" value="root"></property>
        <property name="password" value="root"></property>
    </bean>

    <!--開啓spring 對註解 AOP 的支持-->
    <aop:aspectj-autoproxy></aop:aspectj-autoproxy>

</beans>

5 單元測試

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:bean.xml")
public class AccountServiceTest {

    @Autowired
    private IAccountService as;

    @Test
    public void testTransfer(){
        as.transfer("Mike","Jenny",100f);
    }

}